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Showing 1 to 20 of 31 for “"energy release rates"”.
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Developments in Extended Finite Element Methods for Extraction of Strain Energy Release Rates and Computational Nanomechanics for SWCNT Aggregates
… (XFEM) framework, is proposed to compute Strain Energy Release Rates (SERRs) directly from Irwin's integral. Crack tip enrichment functions in XFEM allow for evaluation of integral quantities in closed form (for some crack configurations studied) and therefore results in an accurate and efficient …
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Finite Element Analysis of Probe Induced Delamination of a Thin Film at an Edge Interface
Energy release rates are extracted from non-linear finite element analyses of a thin film bonded to a rigid substrate that is shaft-loaded at its free edge. This geometry is of interest because it simulates a probe test that has proven to be useful in characterizing the adhesion of thin, …
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Hydration-Induced Plasma Surface Modification of Aluminum Nanoparticles for Power Generation in Oxygen Deficient Environments
An approach to increase the energy release rate from aluminum (Al) combustion is to modify the alumina (Al2O3) passivation shell surrounding the Al fuel core. One approach uses atmospheric plasma treatment to physically reduce the Al2O3 shell thickness while simultaneously exposing the defected …
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Catastrophe Model for the Onset of Fast Magnetic Reconnection
… magnetic reconnection facilitates the rapid release of energy stored in stressed magnetic fields into the surrounding plasma. Much effort has gone into understanding how the energy is released so fast. Collisional (Sweet-Parker) reconnection, based on resistive magnetohydrodynamics (MHD), is …
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Effect of temperature on the fracture behavior of lead-free solder joints
… are recorded and used to calculate the fracture energy release rates. The fracture surfaces and the crack path analyses are conducted with a scanning electron microscope to understand the effect of temperature on the mechanism of fracture. These results provide new information to manufacturers of …
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Delamination buckling, postbuckling, and growth in axially loaded beam-plates
… buckling load and postbuckling solution. The energy release rate is then determined using the postbuckling solution. Curves are provided to show the effect of delamination length and location on buckling loads, energy release rates, and strengths of the beam-plates. The problem of buckling and …
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Mechanics of swellable elastomeric seals
… finite element simulations, we characterize the energy release rates for the growth of cracks in the regions of high stress concentration at the ends of the seal. We show that, despite the linear Saint-Venant solution not being valid at the ends, it correlates the energy release rates obtained in …
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Self-healing of delamination damage in glass/epoxy composites using catalyst functionalized fibers
… damage. Recovery of up to 10% of critical strain energy release rates is observed. Minimal recovery is attributed, in part, to weak bonding between the polymerized DCPD and the surrounding materials. Tortuous crack paths limit interfacial fiber/matrix de-bond required to expose the catalyst coated …
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A study of blister tests for film adhesion measurement and fracture efficiency of tests for adhesive bonds
… fracture efficiency. Therefore, gross inelastic energy dissipation in the film specimen may occur when using the membrane peeling tests, and may result in large errors in the film adhesion measurement when only elastic material response is considered in the analysis. As a result, the use of a …
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Structural and Thermal Properties of Ignition Resistant Coatings for Reusable Rocket Engines
… When compared to the theoretical stresses and energy release rates at the interface, the coating is expected to survive modern flight conditions. microstructural modification via experimental characterization and numerical analysis of delamination, could make these coatings suitable for modern …
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Mechanisms and mechanics of non-structural adhesion
… into the mechanisms of adhesion and debonding energy associated with the cling between polymeric films and various substrates is presented first. The thermodynamic work of adhesion, electrostatic attraction, and substrate roughness apparently play significant roles in the cling of a film to a …
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Mechanics, Design, and Fabrication of Metal-Graphene Composites
… by atomistic simulations and by comparing energy release rates. Metallic systems that do not deform by dislocations like metallic glasses, NiTi etc. are reinforced with graphene and are also examined by atomistic simulations. In addition, a novel metal-graphene composite in which the metal …
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A Study of Magnetic Reconnection: From 2D Energy Release to 3D Spreading and Localization
… is a plasma process in which stored magnetic energy is converted into thermal and kinetic energies of the surrounding plasma. Oppositely directed magnetic field lines break and cross connect due to a dissipative mecha- nism. The now bent, reconnected field lines retreat from the X-line (the …
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The development of the peninsula blister fracture test for adhesively bonded joints
… geometry benefits from both a constant strain energy release rate over the major portion of the debond length and a high strain energy release rate at any given pressure. Applications of this technique to several adhesion systems were conducted. Although some of these systems haven't been …
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Autohesion model for thermoplastic composites
… were refractured and the critical strain energy release rates (G<sub>IC</sub>) were measured. The pressure was found to be a key factor in the healing process. Temperature and time dependencies of the interply bond development were also observed. The non-isothermal autohesion model …
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Topics in Energy Release and Particle Acceleration in the Heliosphere
This thesis investigates both the release of energy in solar flares, and the acceleration and transport of particles in various astrophysical situations. While numerical simulations are central to this thesis, these are always motivated by analytical arguments. A review of flare energy release is …
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Chemo-poro-elastic fracture mechanics of wellbore cement liners : the role of eigenstress and pore pressure on the risk of fracture
… series solution to the stress state. Finally, energy release rates are derived for (i) the micro-annulus formation along the steel-cement and rock-cement interfaces, and (ii) the occurrence of a single radial fracture emanating from the steel-cement interface.
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The effect of cooling rate on toughness and crystallinity in poly(ether ketone ketone) (PEKK)/G30-500 composites
… fabrication system’s air cleaner. Cooling rates of 2°C/min, 4°C/min, 6°C/min, and 8°C/min resulted in composites with crystallinities of 33%, 27%, 24%, and 23%, respectively. The principal investigation of the effect of cooling rate on crystallinity and mode I and mode II strain energy …
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Effects of Voids on Delamination Behavior Under Static and Fatigue Mode I and Mode II
… decrease in modes I and II maximum cyclic strain energy release rates and fatigue life. Fractographic features allowed relations to be drawn between fracture surfaces and mechanical properties of the composite, and to investigate the differences in the fractographic features between panels …
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Instability-related delamination growth of embedded and edge delaminations
… size on the distribution of the strain energy release rate components along the delamination front; and 3) performance of a combined experimental and analytical study of instability-related delamination growth (IRDG). Two material systems (AS4/PEEK and IM7/8551-7) and two stacking …
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